Secure Error Handling in APIs: How to Implement Global Filters and Prevent Sensitive Data Leaks

Error handling is one of the most overlooked attack surfaces in API security. While developers focus on authentication, authorization, and input validation, a poorly configured error response can silently leak database schemas, internal file paths, stack traces, and environment details handing attackers a roadmap to your system. The solution is secure, centralized error handling, intercepting all exceptions at a global level, sanitizing what gets returned to the client, and ensuring that internal details stay internal. In this guide, you'll learn how to implement global exception filters in NestJS, design a secure error response schema, prevent sensitive data leaks, and structure error handling for both development and production environments. Why API Error Responses Are a Security Risk Consider this typical unhandled exception response from an Express or NestJS app in development mode: { "statusCode": 500, "message": "QueryFailedError: column \"usr.emailAdress\" does not exist", "stac